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草业学报 ›› 2018, Vol. 27 ›› Issue (1): 86-96.DOI: 10.11686/cyxb2017116

• 研究论文 • 上一篇    下一篇

秋末刈割处理对沙地苜蓿冬季根颈非结构碳氮的影响

朱爱民1, 张玉霞1, *, 王显国2, 田永雷1   

  1. 1.内蒙古民族大学农学院,内蒙古 通辽 028041;
    2.中国农业大学动物科技学院,北京 100083
  • 收稿日期:2017-03-16 修回日期:2017-05-05 出版日期:2018-01-20 发布日期:2018-01-20
  • 通讯作者: E-mail:yuxiazhang685@163.com
  • 作者简介:朱爱民(1992-),男,安徽宿州人,在读硕士。E-mail:m15344081730@163.com
  • 基金资助:
    国家行业公益项目(201403048-2),内蒙古自然基金(2014MS0315)和内蒙古自治区饲用作物工程技术研究中心开放基金项目(MDK2016019)资助

Effects of autumn cutting on the non-structural carbon and nitrogen content in the root collar of alfalfa

ZHU Ai-min1, ZHANG Yu-xia1, *, WANG Xian-guo2, TIAN Yong-lei1   

  1. 1.College of Agricultural Sciences, Inner Mongolia University for the Nationalities, Tongliao 028041, China;
    2.College of Animal Science and Technology, China Agricultural University, Beijing 100083, China
  • Received:2017-03-16 Revised:2017-05-05 Online:2018-01-20 Published:2018-01-20

摘要: 为解决科尔沁沙地紫花苜蓿秋末是否应该刈割及最佳刈割时期的争议,对秋末不同时期刈割处理和未刈割的8个紫花苜蓿品种根颈中非结构碳氮物质变化进行了测定。结果表明,未刈割紫花苜蓿根颈中可溶性糖含量、淀粉含量均显著高于不同时期刈割的紫花苜蓿根颈中含量(P<0.05);土壤冻融交替期(11月1日),秋末晚割(10月15日)紫花苜蓿根颈中可溶性蛋白含量和游离氨基酸含量与未刈割相比均显著增加(P<0.05)。土壤封冻期(12月1日),未刈割紫花苜蓿根颈中可溶性蛋白、游离氨基酸含量均高于不同时期刈割根颈中含量,其中游离氨基酸含量晚割(10月15日)均显著低于未刈割根颈中含量(P<0.05),可溶性蛋白含量10月1日刈割均显著低于未刈割根颈中含量(P<0.05),且10月1日刈割后苜蓿根颈中游离氨基酸、可溶性蛋白含量经过“增长-降低-稳定”过程。两时期测定结果不同,可能与刈割后苜蓿再生长有关;未刈割与刈割处理不同紫花苜蓿品种间根颈中可溶性糖、淀粉、可溶性蛋白、游离氨基酸含量存在差异;未刈割紫花苜蓿根颈中C/N显著大于不同时期刈割处理的根颈中C/N。初步结论为:科尔沁地区冬季寒冷、降雪少,秋末刈割导致地上碳水化合物无法向根系运输,且刈割后苜蓿再生长消耗根系营养物质。为确保紫花苜蓿安全越冬保障苜蓿根系中积累大量储藏物质,不适宜秋末敏感期刈割或选择种植刈割后根颈中C/N高的紫花苜蓿品种如东苜1号等。

Abstract: To determinate the effect of autumn cutting management on alfalfa (Medicago sativa) growing in sandy soil in Horqin, changes in content of non-structural carbon and nitrogen compounds in the root collar of 8 alfalfa varieties with and without cutting were analyzed. The results showed that the starch and soluble sugar contents without cutting were significantly higher (P<0.05) than those cut at different times. Cutting on the 1st of November (when soil was regularly freezing and thawing) and October 15th resulted in higher free amino acid and soluble protein content compared to no cutting. However, cutting on December 1st (frozen soil) and no cutting resulted in higher free amino acid and soluble protein content than other cutting treatments. The free amino acid content after cutting on October 15th was significantly lower (P<0.05) than the uncut and cutting on October 1st resulted in significantly lower (P<0.05) soluble protein content than uncut plants. Both the free amino acid and soluble protein content with October 1st cutting initially increased, decreased and then stabilized. The different results from these cutting times may be related to alfalfa regrowth after cutting. Soluble sugar, starch, soluble protein, and free amino acid differed varieties, with cutting and without cutting. The C/N ratio without cutting was significantly higher (P<0.05) than that in cut plants. These results suggest that the cold winter temperatures in the Horqin region and the relatively light snow cover reduces transportation of above-ground carbohydrates to roots and that regrowth after cutting utilizes root nutrients. For these reasons, cutting in late autumn should be avoided to ensure sufficient accumulation. Alfalfa varieties with high root C/N content, such as Dongmu No.1, may offer advantages in this environment.